Boom type excavator



Feb. 23, 1943. H. HOLLMANN ET AL BOOM TYPE EXCAVATOR Filed June 21, 1941 2 Sheets-Sheet l h 0 681112 man INVENTORS ATOR.NEY

2 Sheets-Sheet 2 Filed June 21, 1941 WW? w k Y m m M r J .R z MWWM m. M P A w wcp Y Y m m @N am a n \N l u Yum Q R H, P. wm .m 3w V 9%. Q NN QHN mm N WN S n n M mu W Patented Feb. 23, 1943 UNITED STATES PATENT OFFICE BOOM TYPE EXCAVATOR Hubert Hollmann, William G. Van Voorhis,

Charles L. George, and Ralph 0. Gerdeman,

Findlay, Ohio, assignors to 'The 'BiickeyeTram' tion' Ditche'r'Company, Findlay, 0hio,- 'a' corpo= ration of Ohio Application June 21, 1941, Serial No. 399,052

8 Claims.

This invention relates to "excavating machines but more particularly totrenching or ditching machines employing a boom and an endless-series of excavatingbuckets.

An object is to produce'a new'and improved means for retammgandsupporting the bucket carrying boom in'the raisedor traveling position in such manner that as a practical matter-ghability of the boom dropping due to defect or failure on the part ofthe hoist or holding means, is obviated.

Another object is to produce a simple and-ellicient' mechanisrn'for imparting raising andlowering movements to the bucket carrying boom, which is'posit'ive' in operation, sturdy and reliable in construction, insures the holding-of the boom in the desired position" during working or traveling,'and which is operative to shift the weight of the booinwhen' in'raisedor traveling position closer to the 'centerof gravity of the machine.

A further object is to provide a guide for-di-' recting the dirt from the buckets to the discharge conve'yorwit'h means for automatically accommodating itself to the adjusted position of the boom'thereby reducing the height of the machine and enabling the" guide to be properlypositioned at all timeswith relation to the boom. A still further object is toreduce the height of an excavator of the above type both during excavating and'traveling operations.

A still further object is to produce an excavator of the boom type in which the boom can be positively crowded or forced into the ground and maintained in the"desi'red working position.

A still further object is to improve the construction of the boom enabling variations in length thereof to be secured and aifording excavator chain take-up.

Further objects and advantages of the invention will hereinafter appear andfor purposes of illustration but not of limitation, an embodimently in section of a portion of the machine shown in Figure 1, certain of the parts being omitted for purposes of clarity;

Figure '3 is an enlarged transverse sectional view substantially on the Iin-33 of Figure 2;

Figure 4 is an enlarged fragmentary diagramcrawler units and supports a power plant I2.

which may be in the formof an internal combustion engine, the weight of which. is in counterbalancing relation toth'e boom type eXcava-,

tor generally designated at E. Spaced vertically above the main frame I0 is a pair of laterally spaced vertically inclined tracks l3 which are T shaped in cross section and which incline downwardly from the rear end ofthe machine. The tracks are suitably supported by the series of uprights I4 which are secured at their lower end portions to themain frame ll]. Mounted for movement along the tracksl3 is a pair of slides l5 which, asindic'ated' on Figure 3, cmbrace tracks I3.

boom H being pivotally connected to the trun= nions Ila carried by the slides IS. .The inner end portion of the boom ll accommodates laterally spaced sprockets !8 which are fixed. to the shaft l6 and over each of the sprockets I8 is trainedv an endless chain 19 which at its oppo-v site end, passes over one of the laterally spaced rollers 20 mounted at the outer endof the boom.

l9 and suitably secured welded. to the tube as well as each of the arms 25, is a metal plate 22a. Welded to the rear edge of the metal plate 22a is a rod 221) which is also rigid with each of the arms 25. By means of the shaft 22,'r0d 22b and plate 22a, it will be apparent that the slides l5 are rigidly secured together and the tendency .of the slides binding.

on the tracks is eliminated.

Secured to each end portion of the shaft [6 is a sprocket wheel 26 which is connected by a chain 21 to a sprocket wheel 28 which is secured to a Suitably journaled in the slides. I5 is a shaft It, the upper end portion of the.

shaft 23 mounted within the tube 22. It will thus be apparent that rotation of the shaft 29 imparts movement to the endless series of excavating buckets 2|, as will be readily understood. Power is transmitted to the shaft 29 through a sprocket and chain connection 30 which in turn derives its power from the internal combustion engine l2 in any suitable manner through the transmission T and transverse shaft 3|. The shaft 3| is connected to the shaft 29 by an adjustable arm 32 in order to maintain these shafts in the desired spaced relation during the raising and lowering of the boom, as will hereinafter appear. This arrangement maintains the chain drives taut at all times and eliminates the necessity for chain tighteners in the form of idlers. The detail construction of this drive arrangement forms no part of the present invention and reference is here made to the patent to Charles L. George, 1,892,526, dated December 2'7, 1932, for a more detailed description and illustration thereof.

In this instance, hydraulic means is employed for actuating the slides l and associated parts along the tracks [3 thereby to effect movement of the boom and endless chain excavator to and from any desired working position. As shown, a pair of laterally spaced hydraulic cylinders 33 is mounted on a supporting panel 34 which is disposed above the power plant l2. As shown the forward end of each cylinder 33 is pivotally connected to a bracket 35 on the panel 34 to afford swinging movements in vertical directions. Within each cylinder 33 is a piston 36 having a piston rod 31 which has a clevis 38 at its outer end. The clevis 38 is pivotally secured by a pin 39 to a support 40 which is rigid with the cross shaft 22. As will hereinafter more fully appear, the movement of the pistons 36 to the right of the cylinders 33 (Figure 2) will elevate the boom excavator E and movement of the pistons in the opposite direction will positively move the excavator to working or excavating position. Each of the cylinders 33 has a pipe 4| which extends from the left-hand end of the cylinder to a valve box 42 and a pipe 43 which extends from the righthand end of each cylinder to the valve box 42 containing a center lock valve of well-known type. Liquid is forced by a pump 44 through a pipe 45 to the valve box 42 and. by adjustment of a suitable valve (not shown), the fluid is forced to the desired end of the cylinders 33 in accordance with the desired direction of piston movement.

The excavator boom I! is of beam; metal of box-type construction and telescoping with the outer end thereof is a slide 46 which carries the rollers 20 at the outer end thereof. Engaging the inner end of the slide 45 is a coil spring 41 against the opposite end of which bears the head of an adjusting screw 48. The outer end of the adiusting screw 48 is accessible through an opening in the under side of the boom so that upon applying a wrench, it will be apparent that the tension imposed upon the coil spring 41 may be increased or diminished. Inasmuch as the space afforded for access to the adjusting screw is limited, a ratchet type wrench is desirable. In this manner lengthening of the boom I! to a limited extent may be accomplished, In addition, the spring device also serves as an automatic adjustable chain take-up. thereby maintaining the chains under proper tension. The chains l9 engage a series of spaced guide rollers 49 which are carried by the boom ll.

An important feature of the invention resides in the provision of means for assisting in the vertical movements of the excavator boom and for assisting in the holding of the boom when the latter has been moved to its raised or traveling position. For this purpose, a pair of links 50 pivotally connect the boom I! to the rearmost upright l4. Each link 50 is pivoted to a laterally extending bracket 5! rigid with an upper portion of the boom, somewhat above the center of the boom. The opposite end of each link 50 is pivoted to a bracket 52 which is rigid with and projects rearwardly from the rearmost frame upright l4. It will be manifest that the links 50 upon movement of the slides [5 to the right of Figure 1, will cause the outer end portion of the boom excavator E to swing upwardly until it finally reaches the position indicated by broken lines on Figure 1 and with the links 50 in upright position inclined slightly to the right or toward the adjacent supporting upright l4. In this position, the links 50 support the weight of the excavator E and in view of the fact that the links are in vertically inclined position, they militate against accidental dropping of the excavator in case, for example, some leakage might occur in the hydraulic elevating mechanism. In addition, it will be manifest that when the boom is raised to its traveling position, the weight of the excavator is shifted forwardly closer to the center of gravity of the machine.

It will also be apparent that upon movement of the slides l5 to the left of Figure 1 by the above described hydraulic mechanism, the excavator E is positively forced into its digging or working position so that weight of the parts alone is not relied upon. The two slides I5 are rigidly connected with each other as above explained so that any tendency of the slides to bind or cock, due, for example, to a greater force being exerted by one of the hydraulic pistons than the other, is obviated, so that in either direction of movement of the boom excavator E, the parts move uniformly and with a minimum amount of friction.

It will readily be apparent that in the digging operation, the excavting buckets 2| successively discharge their loads upon a conveyor 53 in the form of an endless belt which projects laterally of the machine and is driven in any suitable manner from the main power plant l2 so as to discharge the dirt laterally of the machine as the machine advances. The dirt is thrown against a scoop-shaped shield or deflector 54 which is vertically inclined and so disposed as to allow the contents to pass by gravity to the conveyor 53. Opposite sides of the lower end of the shield 54 are pivoted at 55 to brackets 56 which are rigid with and project rearwardly from an intermediate frame upright l4. On the underside of the shield 54 is a depending plate 51 which has a rearwardly disposed relatively flat contact surface 58 which merges with a forwardly disposed upwardly inclined contact surface 59. The plate 51 is spaced forwardly from the pivotal support 55 so that the weight of the shield 54 causes the fiat contact surface 58 normally to bear upon rollers 60. The rollers are carried by the adjustable arms 32 of the constant center drive mechanism above described.

As a consequence, it will be apparent that in the working position of the boom excavator E, the shield 54 is disposed in the position indicated by the full lines on Figure 4 in which the flat contact surface 58 rests against the rollers 60. When the boom excavator E is raised to its horizontal or traveling position, it will be manil. a e 3 i and 45v here wi e hi o:-. wine n lo estth t,theafiustab armsfillre ls ithefri i1 F e ;1': 9i ibmke rlt ssos i pn show n uphi r 99 1 suc -.mQ e n he wei wise 'direction or to ishe broken, line-,- position 5, shown on: lf'igure 4.

,It will be ';apparent,;that; the shield is automatically lowered hen theboom excavator is contact surface :59;;-operating;to swing the shield to the desired position. When the boom is in traveling position, not only is the better distribution of weight accomplished, but also the height of the machine is accordingly reduced.

It is to be understood that numerous changes in details of construction, arrangement and operation may be effected without departing from the spirit of the invention especially as defined in the appended claims.

What we claim is:

1. In an excavator, a main frame, an excavating boom disposed at one end'of said main frame, a track disposed above said main frame and carried thereby, said track having a pair of laterally spaced track members, a shiftable member engaging each of said track members, means providing a pivotal connection between the upper end of said boom and each of said shiftable members, means for rigidly connecting said shiftable members together, hydraulic means for imparting shifting movement to said shiftable members along said track members, said hydraulic means including individual piston and cylinder members engageable respectively with opposite sides of said rigid connection, a link connection between said boom and said main frame whereby upon movement of said shiftable members in one direction, said boom is swung to a substantially horizontal position with the weight thereof advanced toward the center of gravity of the machine, means for driving said boom excavator in any position of adjustment thereof, a spoil conveyor for discharging dirt excavated by said excavating boom laterally of the main frame, a movably mounted shield for directing dirt from the excavator to said conveyor, and means for automatically moving said shield upon elevation of said boom to traveling position in such manner as to reduce the height of the machine, said last means being operative to restore the shield to normal position when the boom is returned to digging position.

2. In an excavator, a main frame, a boom disposed in vertically inclined position when in excavating positionisaid boom having an endless series of excavating buckets, means providing a pivotal mounting for the upper end of said boom, a link connection between an upper portion of said boom and said main frame in such manner that the boom is elevated to a substantially horizontal position when the upper end thereof is shifted in a substantially horizontal direction, means for shifting the upper end of said boom in a substantially horizontal direction, a shield for deflecting dirt excavated by said boom excavator, a pivotal mounting for said shield, and means for automatically varying the position of said shield in accordance with the position of said boom.

3. In an excavator, a main frame, a boom ex- :fi Yei c e ii dz irq aend:0i ,sa dgmainz frame,

' hgield, res ting;ag ainst-,said roller, and a pivotal i@un ne f a d- Shield, said cam surface being vertically:disposedsarm adapted.- to swing from a one ;-position to another; from; the-raised to loweredposition of--the exoavator, a .roller on said arm, a-,cam ,surface; onythe under sideoflsaid so; designed wthat upon swinging movement of said agm, to; the posit-ion occupied, when the .ex-

1 cayatorisin raised position,- the shield drops .by

ldgravity thereby lowering :the height of the-.ma-

chine for traveling purposes and avoiding interference with the boon when raised.

4. In an excavator, a main frame, an excavator boom disposed in a vertically inclined position at one end of said frame when excavating and in a substantially horizontal position when fully hoisted, means for imparting reciprocatory movement to the upper end of said boom along an approximately horizontal path, a link connection between a rear end portion of said main frame and said boom at a point above the center thereof, whereby said link is rearwardly disposed when said boom is in digging position and is disposed upwardly with the upper end portion inclined forwardly toward said frame when in fully hoisted or transporting position, and a stop for limiting the forward inclined movement of said link thereby to retain said boom in its fully hoisted or transporting position.

5. In an excavator, a main frame, an excavator boom disposed in a vertically inclined position at one end of said frame when excavating and in a substantially horizontal position when fully hoisted, means for imparting reciprocatory movement to the upper end of said boom along an approximately horizontal path, a relatively short link pivotally connected at one end to the rear end of said frame and at the opposite end to said boom at a' point above the center thereof, said link being toggled over center when the boom is in hoisted position, and a stop for said link in such toggled over position.

6. In an excavator, a main frame, an excavator boom disposed in a vertically inclined position at one end of said frame when excavating and in a substantially horizontal position when fully hoisted, said boom having an endless series of excavating buckets, approximately horizontal track means on the upper portion of said frame, slide means having translatory movement along said track means, trunnion means on said slide means providing a pivotal support for said boom, means separate from said trunnion means for driving said endless series of buckets, and a relatively short link connecting said frame and said boom at a point above the center of the latter, said link moving to a forwardly inclined position when the boom is fully hoisted.

7. In an excavator, a main frame, an excavator boom disposed in a vertically inclined position at one end of said frame when excavating and in a substantially horizontal position when fully hoisted, said .boom having an endless series of excavating buckets, approximately horizontal track means on the upper portion of said frame, slide means having translatory movement along said track means, trunnion means on said slide means providing a pivotal support for said boom, means separate from said trunnion means for driving said endless series of buckets, said main frame including upright support at the rear end thereof, and a relatively short link pivotally connected at one end to said upright support and at its opposite end to said boom at a point above the center of the latter, said upright providing a stop for limiting the upward swinging movement of the link and to hold the latter in a forwardly inclined position when the boom is fully hoisted.

8. In an excavator, a main frame, an excavator boom disposed in a vertically inclined position at one end of said frame when excavating and in a substantially horizontal position when fully hoisted, said boom having an endless series of excavating buckets, approximately horizontal track means on the upper portion of said frame,

slide means having translatory movement along said track means, positive reciprocatory means for actuating said slide means along said track means, trunnion means on said slide means providing a pivotal support for said boom, means separate from said trunnion means for driving said endless series of buckets, and a relatively short link connecting said frame and said boom at a point above the center of the latter, said link moving to a forwardly inclined position when the boom is fully hoisted.

HUBERT HOLLMANN. WILLIAM G. VAN VOORHIS. CHARLES L. GEORGE. 4 RALPH O. GERDEMAN. 

